VR7 and VR10

Our Goal:
On October 2, our goal was to put Peaches on the VR7 reinforcement schedule.  On October 3, our goal was to put Peaches on the VR10 reinforcement schedule.

In a variable ratio schedule of reinforcement, instead of providing a reinforcer when a behavior has occurred a fixed number of times, it makes it possible to vary the requirement around some average.  For example, instead of reinforcing every fifth lever press, it might reinforce after the second, the eighth, the sixth, the forth, or so on.

Procedure:
On October 2, the session started at 8:47 A.M and lasted 25 minutes and 8 seconds.  Peaches pressed the lever 651 times and she received 93 reinforcements.  She weighed 216.8 grams, 4.8 grams above her target weight.

On October 3, the VR10 session started at 8:43 A.M and lasted 30 minutes.  Peaches pressed the lever 893 times and received 89 reinforcements.  She weighed 216 grams, 4 grams above her target weight.  

Results:
In the VR7 session, Peaches went into the operant box she headed straight to the food hopper, she then moved to the lever.  She pressed the lever rapidly and continued pressing it till she heard the magazine sound.  In between long series of presses she would stop and look at the food hopper for a reinforcement, then would continue pressing the lever at a rapid pace limiting the number of PRPs (post-reinforcement pauses).  One problem we were still dealing with is having to manually provide reinforcements because the magazine wouldn't do it when it rotated.  Peaches also exhibited a new behavior, rolling over.  She would grab onto the food hopper and twist her body so that she could look up the food hopper where the pellet would drop, then she would roll over so that she was back on her paws.

Peaches Learning VR7 (In this video, you can see Peaches pressing the lever very rapidly then pausing to check the hopper then continuing to press in order to get reinforcement.  You can also see me manually providing a reinforcement to Peaches)

During the VR10 session, Peaches explored the box before heading in the direction of the food hopper and lever.  She experienced very rapid run rates, she would press the lever multiple times if no reinforcement was provided she would press the lever more rapidly until she heard the magazine.  There was an absence of PRPs (post-reinforcement pauses).  Once again, the magazine wouldn't always release pellets therefore we had to manually provide them.

Peaches Learning the VR10 schedule

VR10 Schedule (In this video, you can see Peaches pressing the lever rapidly, checking the hopper then continuing to press the lever at a more rapid rate.  You can also see me having to manually provide Peaches with a reinforcement)

Cumulative Record for VR7

Cumulative Record for VR10

Discussion:

For both sessions, Peaches continued to press the lever until she was reinforced.  Even if there was no reinforcement, she would press the lever at a more rapid rate until she was reinforced.  Peaches progressed very rapidly through this schedule of reinforcement, we never had to spend more than one day on the same level.  Through this schedule, Peaches PRPs began to appear less and less.  It was as if she would get frustrated if she had pressed the lever for a certain number of times and not get reinforced she would press the lever even more rapidly thinking that it would provide a reinforcement faster.  She even showed us a new behavior, rolling over.